Spring



A. B.'DAV|S.

Car Spring. N0. 22,941. Pamed Feb. 15, 1859.

Witnesses: Inventor I lMtFHTQ-LITHD, CD, N.Y. (USBURNE'S PRDCESS.) v

sra'rns natuur oriana.

AUGUSTUS" n. navrsf orl Pi-IiuADELrHiA, rENNsi/"Lvaxia:

RAILROAUCAR SPRING.-

Speccation forming part of LettersPatent No. 22,941,datetlFeb'ruary15,1859; Ressied'Janu ary`f6,=1863, Nos.

To all whom it may concern:

Be it known that I, AUGUSTUS B. DAVIS, ofy

by means of a bolt or bolts, the said box containing a number of spiralsprings confined vertically between the bottom of the box and the lid,and retained in their proper position laterally by means of lugs orother suitable devices, the said lid having a limited ver tical but nolateral movement independent of the box, and the Whole forming a newmanufacture; namely, a railroad car-spring, easy in its action,portable, selcontained and readily adapted to its place in the car.

In order to enable others to make and use my invention, I will noWproceed to describe its construction and operation.

On reference to the accompanying drawing, Which forms a part of thisspecification; Figure 1, is a sectional elevation of my improvedmanufacture of railroad car spring. Fig. 2, a sectional plan on the linel, 2 (Fig. l).

A is a metal casing, the precise form of which is not material, althoughI prefer making it square or oblong, as these forms admit of itscontaining the greatest number of springs in proportion to its size. Thecase is closed at one end and open at the other, for the admission of aseries of spiral springs B. A plate C tits, so as to move freely, intothe open end of the casing, and, betiveen the opposite end of the latterand the plate, the spiral springs are coniined longitudinally, Whilethey are retained in their proper lateral positions, and prevented fromcrowding on each other, by projections a both in the casing and on theinside of the plate. A bolt D' passes through both the casing and theplate, and is furnished at one end With a head al, which, fitting intothe beam which rests on or against the casing, serves to maintain thelatter in its proper position.

It is desirable that the spiral springs, in

order` that they may retain their efcient elasticity, should never becompressed beyond a certain limit.

The compression of the springs, in my improvement, is limited by theprojection c on the plate C, which comes in contact with the end of thebox, before the springs have been compressed to a deteriorating extent;the expansion of the springs being limited, by the extent to which theplate C is caused to project into the casing, by the nut e on the end ofthe bolt.

The spiral springs may be made of steel Wire, although I have found thebest and most tenacious iron Wire equally serviceable, if treatedproperly, and much more economical than steel.

In making experiments, With a view of rendering iron Wire serviceable asspiral springs, I have found that, after the Wire has been coiled, thecoil cut to the desired length and subsequently compressed to the extentto Which it has to be limited hereafter, the spring Will not, on theremoval of the pressure, resume its former length, but, on subsequentpressures being applied, provided they do not exceed the limits of thefirst, the spring Will invariably recoil to the extent to Which itexpanded, after the Ie moval of the iirst pressure. Hence the `advantageof the above described arrangement for limiting the compression of thesprings, enabling' me to use in their construction a cheap and easilyWorked materiali. It is also desirable, in order that the springs mayretain their efficiency, that they should not be strained laterally.This tendency is obviated, in my improvement, by the plate C fittinginto and retaining its proper relative position with the casinglaterally, and by the additional precautionary measure, of

employing the projections a to maintain the springs in their properposition, with respect to the casing.

Springs constructed as above, are much more durable, and much more easyin their action, than when a single spiral spring only is used. At thesame time they are cheap, portable, and readily adapted to their places.

The casing or box A is inverted, as shown in Fig. l, in order that itmay afford a lodgment forvvater and dirt.

I Wish it to be distinctly understood, that I lay no claim to anyseparate specific part or any particular device, connected With theabove described spring, but I claim- As a new and useful article ofmanufacture and merchandise, the entire railroad car spring hereindescribed, that is to say, a spring composed of a box or casing having aplate or lid connected and adapted to the same, the said box containinga number of spiral springs confined between and limited 10 in theirmovement by the said box and the lid, and retained in their properposition laterally by lugs or equivalent devices, as herein set forth.

In testimony whereof, I have signed my name to this specification in thepresence of 15 two subscribing Witnesses.

A. B. DAVIS.

Witnesses:

HENRY HoWsoN, HENRY ODIoME.

[FIRST rmNrnD 1911.]

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